Microsoft Build: From Windows 8.1 to Xbox

As promised, Microsoft on Wednesday launched a public preview of Windows 8.1. Speaking to a developer-heavy audience of 5,000, CEO Steve Ballmer introduced the update during the opening keynote at the company's Build conference in San Francisco. The venue demanded attention not only to Win8, whose Modern UI has been the subject of much criticism and debate, but also to the wider Microsoft ecosystem to which developers now have access. Ballmer and other execs largely met this dual mandate by making Win8.1 one of only several major topics discussed throughout the keynote.

Other focuses included opening Bing as a development platform, empowering developers with new tools and creating a cohesive experience across the Windows ecosystem, from smartphones to desktops.